Step Drill Set GEKO G38503, 4 pcs, steps 4–39 mm, conical step bits for sheet metal and plastics

GEKO G38503 is a 4-piece step drill set featuring conical step bits that cover hole diameters from 4 to 39 mm. The bits are designed to drill progressively larger holes in thin materials without changing tools, enabling smooth enlargement and accurate sizing. Intended for tasks that require fast drilling in sheet metal, aluminium, plastics and laminates, this set delivers multiple step sizes per bit for efficient work in light fabrication and electrical installation projects.

Advantages

The conical step geometry allows single-bit progressive drilling, reducing tool changes and saving time. Each bit offers several stepped diameters, which helps produce clean holes with reduced burrs when used at appropriate speeds and feeds. Hardened construction ensures durability for repeated use in thin metal and non-ferrous materials, while the tapered design provides stable centring and controlled chip removal for consistent hole quality.

Suitable for

• Drilling and enlarging holes in sheet metal and aluminium panels
• Creating cable and conduit entries in electrical enclosures
• Working with plastics and laminates for appliance and furniture components
• Light fabrication tasks where multiple hole diameters are required quickly

Key specifications

• Set composition: 4 conical step bits covering stepped diameters from 4 mm up to 39 mm
• Material compatibility: sheet metal, aluminium, plastics, laminates
• Function: progressive hole enlargement with multiple stepped diameters per bit
• Typical applications: light fabrication, electrical installation, maintenance work

How to use

Secure the workpiece and mark the required hole position. Select the appropriate step bit that includes the desired final diameter. Use a drill press or hand drill at moderate speed suitable for the material—lower speeds for metals and higher speeds for plastics—apply steady feed pressure and allow the stepped edges to cut progressively through the material. Back off periodically to clear chips and avoid overheating. Finish the hole by running the last step size through the material to obtain the intended diameter and check for burrs; deburr externally if necessary.

Usage recommendations

For best results in metal, use cutting fluid or light oil, run at moderate rpm and avoid excessive feed force to prolong bit life. When working with plastics, use higher speeds and reduced pressure to prevent melting. Store the bits dry and clean to prevent corrosion and inspect for wear before critical tasks.